Displacement wave

A displacement wave is an artificially generated, highly energetic phenomenon, characterized as a polarized magnetic variation.

In the year 2267, a form of displacement wave was detected when the USS Enterprise was approaching and then in orbit around the Guardian of Foreverplanet. CommanderSpock reported to CaptainJames T. Kirk that their ship was passing through ripples in time. Kirk then ordered LieutenantUhura to report to Starfleet Command that something or someone down on that planet was causing turbulent waves of space displacement. When Kirk asked Spock again about whether the Enterprise should stay in orbit to investigate, Spock told Kirk that it was of very huge scientific importance that they maintain orbit to study the waves. As the landing party would soon discover, the waves were caused by the Guardian of Forever, a time portal–like device that refused to answer Kirk's question as to whether it was a being or a machine. (TOS: "The City on the Edge of Forever")